TO THE SHAREHOLDERS OF

TGS-NOPEC GEOPHYSICAL COMPANY ASA

NOTICE OF ANNUAL GENERAL MEETING

Notice is hereby given that the annual general meeting of TGS‐NOPEC Geophysical Company ASA, reg. no 976 695 372 (the "Company"), will be held on 11 May 2021 at the offices of Schjødt law firm at Ruseløkkveien 16, NO‐0201, Oslo, Norway at 5:00 pm (Oslo time).

Due to the extraordinary situation caused by the COVID-19 pandemic, and in light of the travel and meeting recommendations and restrictions currently in place, the Board has found it necessary to urge shareholders to either vote electronically in advance or submit proxy forms prior to the meeting, and to not attend the meeting in person.

The Company's Articles of Association sets a registration deadline. Shareholders who wish to participate (by proxy) in the general meeting must therefore give notice to the Company by 8 May 2021 at 5:00 pm (Oslo time). A registration form and proxy form are attached hereto as appendix 1.

The Company's Board of Directors (the "Board") has proposed the following agenda:

1. Opening and registration of attending shareholders 2. Appointment of meeting chair and a person to co-sign the minutes 3. Approval of the notice and agenda 4. Approval of the financial statements and Board's report for 2020 5. Approval of auditor's fee 6. Amendment of section 1 of the Articles of Association 7. Amendment of section 3 of the Articles of Association 8. Appointment of members to the Board 9. Approval of remuneration to the members of the Board 10. Appointment of members to the Nomination Committee 11. Approval of remuneration to the members of the Nomination Committee 12. Statement on corporate governance pursuant to section 3-3b of the Norwegian Accounting Act 13. Statement on remuneration principles for senior executives 14. Approval of long-term incentive plan and resolution to issue free-standing warrants 15. Board authorization to acquire own shares 16. Reduction of share capital by cancellation of treasury shares 17. Board authorizations to (a) issue new shares and (b) issue convertible loans 18. Board authorization to distribute dividends

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1 Opening and registration of attending shareholders Chair of the Board, Henry H. Hamilton III, or someone appointed by him, will open the general meeting. A list of attending shareholders will be made.

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2 Appointment of meeting chair and a person to co-sign the minutes The Board proposes that Viggo Bang‐Hansen of law firm Schjødt is elected to chair the meeting. One person attending the general meeting will be proposed to co‐sign the minutes.

3 Approval of the notice and agenda The Board proposes that the general meeting makes the following resolution: "The notice and agenda are approved."

4 Approval of the financial statements and Board’s report for 2020 The Board’s report, the Company's financial statements and the consolidated financial statements

of the Company and its subsidiaries (the Group) for 2020, together with the audit report, were published on 15 April 2021 and are available on the Company's web page, www.tgs.com.

The Board proposes that the general meeting makes the following resolution: "The general meeting approves the Board’s report for 2020 and the Company's financial statements for 2020."

5 Approval of auditor's fee The Board proposes a fee of USD 244,000 to the auditor as the 2020 audit fee for the Company. This

does not include fees related to the audits of the Company’s subsidiaries or other professional services rendered. Note 4 to the Company's Financial Statements and Note 10 to the Group’s Consolidated Financial Statements provide further details on other fees to the auditor.

The Board proposes that the general meeting makes the following resolution: "The general meeting approves the auditor’s fees for 2020."

6 Amendment of section 1 of the Articles of Association The Company has recently expanded the Group’s business activities to encompass the provision of

products and services beyond those related only to the geophysical industry. To reflect this expansion, as well as to simplify the Company’s name and to conform to its logo and trademarks, the Board proposes that, with effect from 1 June 2021, the general meeting resolves to change the Company’s name from TGS‐NOPEC Geophysical Company ASA to TGS ASA and amend section 1 of the Articles of Association to read as follows:

“The name of the company is TGS ASA.”

7 Amendment of section 3 of the Articles of Association to change the principal business area of the Company

As noted in agenda item 6, the Company has recently expanded the Group’s business activities

beyond the geophysical industry to encompass the provision of a wider array of products and services to the broader energy sector. To reflect such broadened scope of business activities, the Board proposes an amendment to the purpose of the Company as set forth in section 3 of the Articles of Association. Accordingly, the Board proposes that, with effect from 1 June 2021, the general meeting resolves to change the business purpose of the Company by amending section 3 of the Articles of Association to read as follows:

“The principal business area of the company is in the provision of data, information and intelligence

and related products and services to the energy industry.

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8 Appointment of members to the Board Reference is made to the Nomination Committee's proposal for the composition of the Board attached as appendix 2 and made available on the Company's web page, www.tgs.com.

9 Approval of remuneration to the members of the Board Reference is made to the Nomination Committee's proposal for remuneration to Board, which is

attached as appendix 2 and made available on the Company's web page, www.tgs.com.

10 Appointment of members to the Nomination Committee Reference is made to the Nomination Committee's proposal for the composition of the committee,

which, together with relevant member information, is attached as appendix 2 and made available on the Company's web page, www.tgs.com.

11 Approval of remuneration to the members of the Nomination Committee Reference is made to the Nomination Committee's proposal for remuneration to its members, which is attached as appendix 2 and made available on the Company's web page, www.tgs.com.

12 Statement on corporate governance pursuant to section 3-3b of the Norwegian Accounting Act Pursuant to section 5‐6 (4) of the Norwegian Public Limited Liability Companies Act, the general meeting shall consider the statement on corporate governance made in accordance with section 3‐ 3b of the Norwegian Accounting Act. The statement is included under the heading "Report on Corporate Governance" in the Company's Annual Report for 2020, which is available on the Company's web page, www.tgs.com. The statement will not be subject to any vote.

13 Statement on remuneration principles for senior executives In accordance with section 6‐16a of the Norwegian Public Limited Liability Companies Act and ancillary regulations, the Board has prepared a statement with respect to the principles for remuneration for senior executives of the Company. The statement is included in the Declaration on Executive Remuneration that is available under the Investor Center/Financial Reports section of the Company's web page, www.tgs.com. Reference is also made to Note 10 to the Group’s consolidated financial statements for 2020 and Item 12 of the Report on Corporate Governance, which are included in the Company’s Annual Report for 2020 that is available under the Investor Center/Financial Reports section of the Company's web page, www.tgs.com.

The Board proposes that the general meeting makes the following resolution: "The statement pursuant to section 6‐16a of the Norwegian Public Limited Liability Companies Act is noted and approved."

14 Approval of long-term incentive plan and resolution to issue free-standing warrants The Board proposes that the general meeting approves a long‐term incentive plan for 2020, cf. the

Norwegian Public Limited Liability Companies Act sections 5‐6 (3) and 6‐16a (1), item no 3.

Since 2015, the general meeting has approved share‐based long‐term incentive plans. These plans are generally secured by free‐standing warrants. From these earlier plans, there are currently outstanding 1,036,710 free‐standing warrants associated with performance share units or restricted share units that, as of 15 April 2021, have been granted but not yet vested and exercised.

The proposed 2021 plan provides for the grant of performance share units (PSUs) and restricted share units (RSUs) on terms generally consistent with the plan approved in 2020. Upon vesting, the

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PSUs and RSUs will represent the right to receive shares of Company common stock as described below. The plan is limited to a maximum of 550,000 shares issuable upon vesting of the PSUs and RSUs. The plan will be administered by the Board. In the event of any merger, reorganization, recapitalization, stock dividend, stock split, combination of shares, share exchange, or other change in shares of the Company, the number of shares then subject to the plan, including shares subject to outstanding awards, will be adjusted in proportion to the change in outstanding shares.

PSUs: Pursuant to the proposed 2021 plan, similar to the 2020 plan, PSUs will be granted to members of the executive and senior leadership teams and will vest three years after the date of grant. Upon vesting, the holder of the PSUs will receive Company shares (if any), with the number of shares issuable determined by multiplying the number of PSUs granted by a factor of 0% to 100%. The factor is determined by performance over a three‐year measurement period against three target metrics as determined by the Board: (i) relative return on average capital employed (ROACE) compared to a peer group of 11 companies, (ii) absolute return on average capital employed, and (iii) sustainability objectives and health, safety and environmental performance (leading and lagging measures). See further details under “2.4 Long Term Incentives 2021” in the Company’s Declaration on Executive Remuneration, which is issued alongside the Company’s Annual Report for 2020 and is available on the Company's web page, www.tgs.com.

RSUs: Pursuant to the proposed 2021 long‐term incentive plan, similar to the 2020 plan, RSUs will be granted to certain non‐executive key employees and will also vest three years after the date of grant. Upon vesting, the holder of the RSUs will receive an equivalent number of Company shares, subject to achieving satisfactory performance against individual goals over the three‐year plan period. The individual performance goals will be based on the performance criteria described in the Company’s Declaration on Executive Remuneration, with a focus on goals that support the corporate targets for financial performance, certain strategic initiatives, employee engagement and sustainability and HSE.

The holders of the PSUs and RSUs must remain employed throughout the vesting period to receive shares issuable under the awards. The holders will also be required to pay the par value, currently NOK 0.25, for each share of Company stock issued pursuant to the PSU or RSU, as applicable. A cash bonus in an amount per unit that is equivalent to dividends that are paid on outstanding Company common stock will be accrued during the vesting period and paid as compensation in accordance with the payout of the awards.

The executive and senior leadership teams are subject to minimum Executive Stock Ownership Guidelines based on a multiple of salary for the CEO (3X), CFO (2X) and the rest of the executive team members and all senior leadership team members (1X). An executive or senior leader has five years from the date the individual is first subject to the guidelines to meet the required level of ownership.

The Board proposes that the Company secure the long‐term incentive plan by the issuance of free‐ standing warrants, to be subscribed for at the time of grant by employees who are granted RSUs and PSUs.

Based on the above, the Board therefore proposes that the general meeting makes the following resolution (one vote to be given for the proposed resolution in its entirety, not for each item of the proposed resolution):

(i) The general meeting approves the 2021 long‐term incentive plan.

(ii) The Company shall issue a minimum of 10,000 and a maximum of 550,000 free‐standing warrants, however subject to the requirement that the number of issued and outstanding free‐standing warrants shall in no event exceed 10 percent of the registered number of shares in the Company at the date of this resolution.

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(iii) Each free‐standing warrant shall give the right to subscribe for 1 share at par value.

(iv) The free‐standing warrants may be subscribed for by employees who are granted rights under the long‐term incentive plan upon the decision by the Board. Existing shareholders shall not have preferred rights to subscribe for the free‐standing warrants pursuant to the Norwegian Public Limited Liability Companies Act section 11‐13, cf. sections 10‐4 and 10‐5.

(v) The free‐standing warrants shall be subscribed for on a separate subscription form at the latest by 31 December 2021. The employees shall not pay for the free‐standing warrants issued.

(vi) The price to be paid for the shares issued on the basis of the free‐standing warrants shall be the par value of the shares.

(vii) The right to request the issuance of shares under the free‐standing warrants follows from the long‐term incentive plan, but so that no free‐standing warrant can be exchanged for shares later than five years following the date of this general meeting.

(viii) The holder of the free‐standing warrants shall not have rights as a shareholder with regard to capital increases, capital reductions, new resolutions on the issue of warrants, dissolution, merger, demerger or reorganization, except with respect to shares that have been issued to and paid for by the free‐standing warrant holder. Upon changes in the Company's share capital, such as share splits, reverse splits and other capital actions as provided for in the long‐term incentive plan, the warrant terms (subscription price and number of shares to be issued upon exercise) shall be adjusted as set out in the long‐term incentive plan.

(ix) Shares issued on the basis of the free‐standing warrants shall give right to dividends declared following the date the shares are issued.

(x) As part of the long‐term incentive plan, the free‐standing warrants cannot be transferred. Any outstanding free‐standing warrants shall be transferred back to the Company as and when the right to exercise the right to request shares in exchange for the free‐standing warrants is lost pursuant to the underlying long‐term incentive plan.

15 Board authorization to acquire own shares The general meeting has in previous years granted the Board an authorization to acquire up to 10%

of the shares in the Company. The Board's current authorization expires at the annual general meeting. To ensure continued flexibility in connection with potential acquisitions or other transactions, as well as to satisfy any obligations deriving from the Company's incentive program, the Board proposes that the general meeting grants a new authorization to acquire own shares in an amount up to 10% of the nominal value of Company's share capital (to be adjusted for any reduction per item 16 below).

The Board therefore proposes that the general meeting makes the following resolution:

(i) The Board is hereby authorized to acquire, on behalf of the Company, the Company's own shares up to 10% of the nominal value of Company's share capital, which pursuant to the current nominal value is up to NOK 2,932,584. The limitations shall be adjusted in the event of share consolidation, share reduction, share splits, and similar transactions.

(ii) The lowest price to be paid per share shall be the par value and the highest price to be paid per share shall be the volume weighted average price as quoted on the stock exchange for the five business days prior to the time of the acquisition plus 5%. The lowest price is equal to

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the current nominal value and shall be adjusted in the event of share consolidation, share splits, and similar transactions.

(iii) Acquisitions and sales of the Company's own shares can take place in the manner that the Board considers to be in the Company's best interest.

(iv) The authorization may be used once or several times. This authority shall be valid until the annual general meeting in 2022, however no longer than until 30 June 2022.

(v) The authorization shall replace previously granted authorizations to acquire own shares.

16 Reduction of share capital by cancellation of treasury shares The Board has, pursuant to the authority granted by last year’s annual general meeting, repurchased

own shares during the course of 2020 and 2021. As of 15 April 2021, the Company holds 235,000 treasury shares.

To secure the issuance of certain performance share units issued pursuant to the 2019 Long‐Term Incentive Plan, the Company must hold 75,000 treasury shares. The Company will also use 9,900 treasury shares to pay the director’s fees; see item 9 on the agenda. In addition, the Company will retain 100,000 treasury shares to provide flexibility, inter alia, to satisfy obligations deriving from the Company's incentive programs and in connection with potential small acquisitions.

The Board therefore proposes that the Company shall cancel 50,100 of the treasury shares the Company holds, and accordingly that the general meeting approves a corresponding reduction of the Company's share capital. The reduction of the share capital does not involve payments from the Company as the treasury shares will be canceled.

The Company's auditor will be available at the general meeting, or immediately before, give its confirmation that there will be sufficient restricted equity capital in the Company after the reduction of capital.

Based on the above, the Board proposes that the general meeting passes the following resolution:

The Company's share capital shall be reduced by NOK 12,525 through cancellation of 50,100 treasury shares held by the Company, each with a par value of NOK 0.25. Section 5 of the Articles of Association shall be amended to reflect the share capital and the number of shares in issue after the share capital reduction.

The Board reserves the right to amend the amount to be canceled, should the Company acquire or need to retain additional treasury shares before the date of the general meeting.

17 Board authorizations to (a) issue new shares and (b) issue convertible loans The annual general meeting has previously granted the Board authorizations to increase the share

capital by issuance of new shares and/or convertible loans.

The current authorizations granted at the annual general meeting in 2020 expire at the 2021 annual general meeting, and the Board therefore proposes that these authorizations are renewed with the same amounts, i.e. an authorization to, in each case, increase the share capital with a nominal amount corresponding to 10% of the current share capital, i.e. up to NOK 2,932,584 (to be adjusted for any reduction as per item 16 above).

Similar to the previous authorizations, the purpose of such authorizations is to provide the Board with financial flexibility (i) in connection with potential acquisitions, (ii) for organic growth of the Company and/or (iii) to strengthen the Company's balance sheet.

To exercise these authorizations in the best possible manner commercially, it may be relevant in certain situations to make a private placement of shares and/or convertible bonds to certain named

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persons and/or entities. The Board therefore requests that the authorizations also encompass the right to waive the shareholders' preemptive rights.

A / Share issue authorization:

Based on the above, the Board proposes that the general meeting grants an authorization to issue shares through the following resolution:

(i) In accordance with section 10‐14 of the Norwegian Public Limited Liability Companies Act, the Board is granted the authorization to increase the Company's share capital by up to NOK 2,932,584 through one or more issuances of new shares or bonus issues. The subscription price and other subscription terms will be determined by the Board.

(ii) The capital increase may be paid in cash, by set‐off or by other contributions in kind. The authorization includes the right to incur special obligations on behalf of the Company, cf. Section 10‐2 of the Norwegian Public Limited Liability Companies Act.

(iii) The shareholders' preemptive rights pursuant to sections 10‐4 of the Norwegian Public Limited Liability Companies Act to subscribe for any new shares may be deviated from by the Board, cf. section 10‐5 of the Norwegian Public Limited Liability Companies Act.

(iv) The authorization shall encompass share capital increases in connection with mergers, cf. section 13‐5 of the Norwegian Public Limited Liability Companies Act.

(v) The authorization is valid until the annual general meeting in 2022, but no later than 30 June 2022.

(vi) The authorization shall replace previously granted authorizations to issue new shares.

B / Convertible loan authorization:

Based on the above, the Board proposes that the general meeting grants an authorization to issue convertible loans through the following resolution:

(i) In accordance with section 11‐8 of the Norwegian Public Limited Liability Companies Act, the Board is granted the authorization to issue loans for a total amount of up to NOK 2,250,000,000 with the right to require shares to be issued (convertible loans).

(ii) The share capital may be increased by up to NOK 2,932,584, provided that the combined number of shares that are issued pursuant to this authorization and the authorization in agenda item 17(a) shall not exceed 10% of the Company's current share capital.

(iii) The subscription price and other subscription terms will be determined by the Board.

(iv) The shareholders' preemptive rights pursuant to section 11‐4 of the Norwegian Public Limited Liability Companies Act may be deviated from by the Board, cf. sections 10‐4 and 10‐5 of the Norwegian Public Limited Liability Companies Act.

(v) The authorization is valid until the annual general meeting in 2022, but no later than 30 June 2022.

(vi) The authorization shall replace previously granted authorizations to issue convertible loans. . 18 Board authorization to distribute dividends The annual general meeting for 2020 authorized the Board to distribute quarterly dividends on the

basis of the 2019 financial statements. The authorization was granted as Norwegian law provides that dividends declared in the period between approval of the financial statements for one year and

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approval of the next year’s financial statements will, absent a shareholder approved audited interim balance sheet, be considered as additional dividends based on the financial statements for the last year approved. The Board has reviewed the Company's financial situation, including the Company's distributable reserves according to the financial statements for 2020. On this basis and in accordance with the Company's dividend policy, the Board proposes that the authorization to distribute quarterly dividend payments be renewed and that the general meeting passes the following resolution:

"The Company authorizes the Board to distribute quarterly dividends on the basis of the financial

statements for 2020. The Board shall, when using the authorization, pass its decision in accordance with the Company’s approved dividend policy. The authorization shall be valid until the Company's annual general meeting in 2022, but no later than 30 June 2022."

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Attendance and registration Shareholders are by law entitled to attend the general meeting in person or by a proxy of their own choice. However, due to the extraordinary situation caused by the COVID‐19 pandemic, and in light of the travel and meeting recommendations and restrictions currently in place, a physical meeting may not be compliant with current laws and applicable regulations. The Board therefore urges shareholders to either vote electronically in advance or submit proxy forms prior to the meeting and to not attend the meeting in person.

Shareholders who wish to attend and vote at the general meeting by proxy may send the proxy form electronically through VPS Investor Services or to DNB Bank ASA, Registrar's Department, within the time limit stated above (5:00 pm (Oslo time) on 8 May 2021). Proxy forms can also be brought and presented at the general meeting.

Notice of attendance must in any event be received no later than 5:00 pm (Oslo time) on 8 May 2021. Notice of attendance can be given electronically through the Company’s website, www.tgs.com/investor‐center or VPS Investor Services, or by providing the completed attendance form to DNB Bank ASA, Registrar's Department, P.O. Box 1600 Sentrum, NO‐0021 Oslo, e‐mail [email protected].

It is specifically noted that pursuant to section 8 of the Company's Articles of Association, the right to attend and vote at the general meeting is reserved for shareholders who are registered in the shareholders' register the fifth business day prior to the general meeting, i.e., on 4 May 2021 (record date).

Advance voting Shareholders not present at the general meeting may, prior to the meeting, cast a vote on each agenda item via the Investor Center of the Company's website, www.tgs.com, or VPS Investor Services. The pin‐code and reference number from the registration form is required to do so. The deadline for advance voting is 5:00 pm Oslo time on 8 May 2021. Until the deadline, votes already cast may be changed or withdrawn. Votes already cast prior to the general meeting will be considered withdrawn in the event of a shareholder attending the general meeting in person or by proxy.

Notice to nominee holders and shareholders with nominee accounts Pursuant to section 8 of the Company’s Articles of Association, a shareholder has the right to cast a vote for the number of shares that are registered to the respective shareholder with the Norwegian Central Securities Depository (VPS) on the fifth business day before the general meeting (i.e., 4 May 2021, the record date). Beneficial owners of shares registered with nominee accounts who wish to exercise their rights at the general meeting must therefore register themselves directly in the VPS registry of shareholders and be registered with the VPS on the fifth business day prior to the general meeting (i.e., 4 May 2021) to ensure their eligibility to meet and cast vote.

Shareholder rights A shareholder has the right to address the general meeting and to bring one adviser and convey to him/her the right of address. A shareholder may table alternative resolutions for items included on the agenda and

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may request in the general meeting that members of the Board and/or the CEO provide available information about matters that may affect the assessment of the Company’s financial situation, including information about activities in other companies in which the Company participates and other matters to be discussed in the general meeting, as further set out in section 5‐15 of the Norwegian Public Limited Liability Companies Act. Requests for information should be put forward no later than ten days prior to the general meeting.

Other matters TGS‐NOPEC Geophysical Company ASA is a Norwegian public limited company subject to the rules of the Norwegian Public Limited Liability Companies Act. As of the date of this notice, the Company has issued 117,303,398 shares, each of which represents one vote. As of 15 April 2021, the Company holds in total 235,000 treasury shares that cannot be voted over. The shares also have equal rights in all other respects.

The following documents, as well as other documents regarding the general meeting, will be available under the Investor Center of the Company's web page, www.tgs.com:

‐ this notice and the enclosed registration and proxy forms ‐ the 2020 annual report and financial statement ‐ the recommendations of the Nomination Committee ‐ the Board's declaration on executive remuneration ‐ the Company's Articles of Association and proposed new Articles of Association

Shareholders may contact the Company through the CEO, Kristian Johansen, by ordinary mail, fax, email or phone (+ 1 713 860 2100), or through the Company’s website in order to request the documents in question.

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Oslo, 20 April 2021

On behalf of the Board of Directors of

TGS‐NOPEC Geophysical Company ASA

Henry H. Hamilton III Chair

This notice has the following appendices, which will be attached to the notice sent to the shareholders:

Appendix 1: Registration form and proxy form Appendix 2: The Nomination Committee’s proposal for composition and remuneration for the Board and Nomination Committee

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Ref no: PIN code:

Notice of Annual General Meeting

Annual General Meeting in TGS-NOPEC Geophysical Company ASA will be held on 11 May 2021 at 5 p.m. at the offices of Schjødt law firm at Ruseløkkveien 16, NO-0201, Oslo, Norway.

Record Date (Share register): 4 May 2021 Registration Deadline according to bylaws: 8 May 2021

The Company accepts votes in advance for this meeting. Registration deadline for advance votes: 8 May 2021 at 5 p.m. Oslo time. Advance votes may only be executed electronically, through the Company’s website www.tgs.com/investor-center/ or via VPS Investor Services.

Notice of attendance The Undersigned will attend the Annual General Meeting on 11 May 2021 and cast votes for:

______own shares.

Notice of attendance should be registered electronically through the Company’s website www.tgs.com/investor-center/ or via VPS Investor Services.

To access the electronic system for notification of attendance through the Company’s website, the above-mentioned reference number and PIN code must be stated. Shareholders who have chosen electronical communication will not receive PIN and reference numbers and can only give notice through VPS Investor services.

Notice of attendance may also be sent by E-mail to [email protected], or by regular Mail to DNB Bank ASA, Registrars Department, P.O.Box 1600 Sentrum, 0021 Oslo, Norway. The notice of attendance must be received no later than 8 May 2021 at 5 p.m. Oslo time

If the shareholder is a legal entity, please state the name of the individual who will be representing the entity: ______

Place Date Shareholder’s signature

Proxy without voting instructions for Annual General Meeting of TGS-NOPEC Geophysical Company ASA If you are unable to attend the meeting, you may grant proxy to another individual.

Ref no: PIN code:

Proxy should be submitted electronically through the Company’s website www.tgs.com/investor-center/ or via VPS Investor Services. To access the electronic system for granting proxy through the Company’s website, the above-mentioned reference number and PIN code must be stated. Shareholders who have elected electronical communication will not receive PIN and reference numbers and can only give proxy via VPS Investor services. Proxy may also be sent by E-mail to [email protected] (scanned form) or by regular Mail to DNB Bank ASA, Registrars’ Department, P.O.Box 1600 Sentrum, 0021 Oslo, Norway.

If you send the proxy without naming the proxy holder, the proxy will be given to the Chair of the Board of Directors of the Company or an individual authorised by him or her.

This proxy must be received no later than 8 May 2021 at 5 p.m. Oslo time.

The undersigned:______hereby grants (tick one of the two)

 the Chair of the Board of Directors (or a person authorised by him), or

 ______(Name of proxy holder in capital letters) proxy to attend and vote for my/our shares at the Annual General Meeting of TGS-NOPEC Geophysical Company ASA on 11 May 2021.

Place Date Shareholder’s signature (Only for granting proxy)

With regards to your right to attend and vote, reference is made to the Norwegian Public Limited Liability Companies Act, in particular Chapter 5. If the shareholder is a Company, the Company’s Certificate of Registration must be attached to the proxy

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Proxy with voting instructions for annual general meeting in TGS-NOPEC Geophysical Company ASA. In lieu of attending the Annual General Meeting in person, you may use this proxy form to give voting instructions. Proxies with voting instructions can only be registered by DNB, and must be sent to [email protected] (scanned form) or by regular Mail to DNB Bank ASA, Registrars’ Department, P.O.Box 1600 Sentrum, 0021 Oslo, Norway. The form must be received by DNB Bank ASA, Registrars’ Department no later than 8 May 2021 at 5 p.m. Oslo time. Proxies with voting instructions must be dated and signed in order to be valid. If you leave the “Name of the proxy holder” blank, the proxy will be given to the Company's Chair of the Board of Directors, or an individual authorised by himr. The undersigned:______Ref no: hereby grants (tick one of the two)

 the Chair of the Board of Directors (or a person authorised by him), or

 ______Name of proxy holder (in capital letters) proxy to attend and vote for my/our shares at the Annual General Meeting of TGS-NOPEC Geophysical Company ASA on 11 May 2021. The votes shall be exercised in accordance to the instructions below. If the sections for voting are left blank, this will be counted as an instruction to vote in accordance with the Board’s and Nomination Committee’s recommendations. However, if any motions are made from the attendees in addition to or in replacement of the proposals in the Notice, the proxy holder may vote at his or her discretion. If there is any doubt as to how the instructions should be understood, the proxy holder may abstain from voting.

Agenda for the Annual General Meeting 2021 For Against Abstention 1. Opening and registration of attending shareholders - - - 2. Appointment of meeting chair and a person to co-sign the minutes    3. Approval of the notice and the agenda    4. Approval of the financial statements and Board’s report for 2020    5. Approval of auditor’s fee    6. Amendment of section 1 of the Articles of Association – change of company name    7. Amendment of section 3 of the Articles of Association – change of principal business area    8. Appointment of members to the Board - - - a. Henry H. Hamilton, Chair    b. Mark Leonard    c. Wenche Agerup    d. Irene Egset    e. Christopher Geoffrey Finlayson    f. Grethe Kristin Moen    g. Svein Harald Øygard    9. Approval of remuneration to the members of the Board    10. Appointment of members to the Nomination Committee - - - a. Christina Stray    b. Glen Ole Rødland as chair    11. Approval of remuneration to the members of the Nomination Committee    12. Statement on corporate governance pursuant to section 3-3b of the Norwegian Accounting Act - - - 13. Statement on remuneration principles for senior executives    14. Approval of long-term incentive plan and resolution to issue free-standing warrants    15. Board authorization to acquire own shares    16. Reduction of share capital by cancellation of treasury shares    17. Board authorizations to (a) issue new shares and (b) issue convertible loans    18. Board authorization to distribute dividends   

Place Date Shareholder’s signature (Only for granting proxy with voting instructions) With regards to your right to attend and vote, reference is made to the Norwegian Public Limited Liability Companies Act, in particular Chapter 5. If the shareholder is a legal entity, the entity’s Certificate of Registration must be attached to the proxy.

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Appendix 2: The Nomination Committee’s proposal for composition and remuneration for the Board and Nomination Committee

TGS-NOPEC Geophysical Company ASA (TGS)

Below is the recommendation from the Nomination Committee (“NC” or the “Committee”) to the Annual General Meeting on May 11, 2021.

Election of Directors

The Nomination Committee proposes that the following candidates are elected to the TGS Board of Directors (“Board”) and to serve as Directors until the Annual General Meeting in 2022. The Nomination Committee recommends the shareholders to vote for each candidate as follows:

Henry H. Hamilton III, Chairman (re-election)

Born 1959. Mr. Hamilton served as CEO of TGS from 1995 through June 2009. He started his career as a Geophysicist with Shell Offshore (1981‐1987) before joining Schlumberger (1987‐1995), where he ultimately held the position of VP and General Manager for all seismic product lines in North and South America. Mr. Hamilton was first elected as a Director in 1998 and as Chairman in 2009.

Mark Leonard, Independent Director (re-election)

Born 1955. Mr. Leonard is currently the President of Leonard Exploration, Inc. He retired in 2007 from Shell Oil Company after 28 years of service. During his tenure at Shell, Mr. Leonard held a number of executive positions including Director of New Business Development in Russia/CIS, Director of Shell Deepwater Services, Director of Shell E&P International Ventures and Chief Geophysicist for Gulf of Mexico. He also serves on the board of the following non‐profits: Society of Exploration Geophysicists Foundation, YMCA of Greater Houston and Hope Center Houston. He was first elected as a Director of TGS in 2009.

Wenche Agerup, Independent Director (re-election)

Born 1964. Ms. Agerup is currently head of Board Governance and Support in Telenor’s Asia HUB in Singapore and chairs the board in Telenor Myanmar and Telenor Pakistan. She previously held positions in Telenor as EVP Corporate Affairs and General Counsel and Head of Group Holdings. From 1997 to 2015, she held various positions in Norsk Hydro, including head of Corporate M&A, plant manager in Årdal and Project Director in hydro UMC in Australia. She served as Executive Vice President Corporate Staffs and General Counsel in Norsk Hydro from 2010 to 2015. Ms. Agerup also served as a board member of Equinor ASA from 2015 to 2020. She was first elected as a Director of TGS in 2015.

Irene Egset, Independent Director (re-election)

Born 1966. Ms. Egset is educated from Molde Regional College and has a four‐year degree (Siviløkonom) Business Administration from NHH, Norwegian School of Economics, Norway. Ms. Egset currently serves as the Chief Financial Officer of Posten Norge, joining in 2019. From 2008 to 2018, she served in various financial leadership roles with Statkraft, joining as CFO of the Solar Power Unit from 2008, transferring to Statkraft Wind Power and Technologies (WPT) in 2010, with responsibility for, i.a., WPT finance employees in UK, Sweden and Norway, and most recently serving as Executive Vice President and CFO of Statkraft from 2016 to 2018. From 2005 to 2008, she was a financial manager for J. F. Knudtzen, and from 2000 to 2005, she served as Controller for Nera SatCom, in charge of financial reporting as well as follow‐up relative to the company’s projects abroad. Ms. Egset held a variety of financial roles at Statoil (now Equinor) from 1992 to 2000, working as a financial consultant on large projects (Veslefrikk/Gullfaks). While at Equinor, she was responsible from 1998 to 2000 for coordinating and

improving reporting to Equinor’s board regarding ongoing projects worldwide. She also served as a board member for Vårgrønn AS, a Norway‐based renewable energy company (JV between Eni and HigtecVision). Ms. Egset began her career in 1988 as a financial manager for Ulstein Elektro (part of the Ulstein Group). She currently holds no other board memberships in any listed companies. She was first elected as a Director of TGS in 2019.

Christopher Geoffrey Finlayson, Independent Director (re-election)

Born 1956. Mr. Finlayson, a geologist and petroleum engineer by training, with nearly 40 years of technical and commercial experience in the oil and gas industry. He received his Bachelor of Science degree with First Class Honours in physics and geology from the University of Manchester in 1977. He joined Shell in 1977 and, during his career, held various leadership roles in exploration and production and liquefied natural gas around the world. Mr. Finlayson joined BG Group plc in 2010 as Executive President & Managing Director, Europe & Central Asia. From 2013 to 2014, he served as the Chief Financial Officer and Executive Director of the BG Group. Currently, Mr. Finlayson serves on the Board of Höegh LNG Holdings Ltd. In addition, he is a non‐executive Chairman of Siccar Point Energy Ltd. and a board member of two other privately held companies. Mr. Finlayson is a Fellow of the Energy Institute. He was first elected as a Director of TGS in 2019.

Grethe Kristin Moen, Independent Director (new)

Born 1960. Ms. Moen holds a Master of Science, Chemical Engineering from the Norwegian University of Science and Technology (NTNU), Trondheim, Norway. She has close to 40 years of experience in leadership positions within the oil, gas and energy industry, 25 years of which (1982‐2007) within Equinor (Statoil) and four years (2007‐2011) within Shell Europe. From 2011 to 2013, Ms. Moen served as Vice President of Petoro AS, responsible for Petoro`s portfolio of mature oil fields, and from 2013 to January 2021, she served as CEO of Petoro. Petoro is a fully Norwegian State‐owned oil company managing the State Direct Financial Interest in Joint Ventures (SDFI/SDØE) with a portfolio of more than 200 licenses and 35 fields in operation offshore Norway. From 2021, Ms. Moen is the owner and CEO at VITE Energy AS. She served as Chairman of the Board in Navion AS (1999) and currently serves as a member of the Board of Directors of Element Logic AS (since 2006) and NEO Energy (UK) (since 2020).

Svein Harald Øygard, Independent Director (new)

Born 1960. Mr. Øygard has a Degree in economics (Cand. Oecon), microeconomics, macroeconomics, finance and monetary policy, industrial economics, statistics and econometrics. From 1983 to the mid‐1990s, Mr. Øygard worked within the Norwegian Ministry of Finance and various other governmental agencies and committees within the Norwegian Parliament. His last position was as State Secretary (Deputy Minister) of Finance of Norway, where he was part of the team leading the work on the 1992 tax reform. From the mid‐1990s, Mr. Øygard held various prominent positions within McKinsey Company, both domestic and abroad, working, i.a., with projects within the oil, gas, power and energy industry. While working within McKinsey Company, he served as Global Knowledge Leader Oil & Gas from 2010 to 2014, leading all knowledge development and research, and led the oil and gas work in South America from 2013 to 2016. In 2009, after the collapse of the Icelandic banking system, Mr. Øygard was called to serve as the Interim Central Bank Governor of the Icelandic Central Bank. From mid‐ 2016, he has been the co‐founder, co‐owner and Chairman of DBO Energy, an oil and gas company focused on accessing and developing mature, producing oil fields in Brazil. From June 2019, Mr. Øygard has been a member of the Board of Directors of AGR Petroleum Services, a subsurface technology advisory company owned by Akastor/Aker; Nettbil, an internet start‐up company; Labrida, a medical equipment start‐up company; and, since 2021, Akershus University Hospital. He is also the initiator, investor and board member of a joint venture between the Norwegian solar company Otovo and Gera Energia, targeting market leadership in rooftop‐solar in Brazil. Presently, Mr. Øygard serves as an independent advisor, and the directorship with TGS will be the only directorship with a listed company.

APPROVAL OF DIRECTORS’ FEE FOR THE PERIOD MAY 12, 2021 TO THE 2022 ANNUAL GENERAL MEETING

The Nomination Committee proposes that the Chairman shall receive in total USD 175,000 to be paid bi‐annually until the Annual General Meeting in 2022.

The Nomination Committee further proposes that each of the Directors, other than the Chairman, shall receive in total NOK 330,000 to be paid bi‐annually until the Annual General Meeting in 2022.

In addition, each of the Directors, other than the Chairman, shall receive 1,650 restricted shares in the Company on May 12, 2021.

No consideration shall be paid for the restricted shares, but the Directors cannot sell any of these shares before May 12, 2023.

The Board’s committee work is, unlike most compensation structures of Norwegian boards, not compensated separately but included in the total compensation of the Board members. As the position as chairman of the two committees entails additional work, the Nomination Committee proposes that the Chairman of the Audit Committee and the Chairman of the Compensation Committee shall each receive a flat fee of NOK 45,000 to compensate for the additional work the chairmanship entails.

APPROVAL OF COMPENSATION TO THE MEMBERS OF THE NOMINATION COMMITTEE FOR THE PERIOD MAY 13, 2020 TO MAY 11, 2021

The Nomination Committee proposes that the fee to members of the Nomination Committee shall be NOK 7,500 per meeting to each member to compensate for the time spent for the works of the Committee. In addition, the Chairman of the Nomination Committee shall be paid NOK 80,000 to compensate for the additional work the chairmanship entails.

ELECTION OF MEMBERS TO THE NOMINATION COMMITTEE

The Nomination Committee proposes that the following candidates are elected to serve as members of the Nomination Committee from May 12, 2021 and for a period up to two years:

Christina Stray, member (re-election)

Born 1968. Presently Chief Compliance Officer in Folketrygdfondet. Previously an Attorney‐at‐Law in Wiersholm Law Firm and Attorney‐at‐Law for Oslo Stock Exchange. Elected as a member of the Committee since 2011.

Glen Ole Rødland, Committee Chairman (re-election as member, new as chairman)

Born 1964. Mr Rødland has 30 years’ experience in shipping, oil and gas service, finance and investment management. He has extensive experience as an analyst and in corporate finance from Investment banking, Private Office and Private Equity. Mr Rødland also has considerable experience as a board member and chairman of several Norwegian public companies and other international companies. He is currently Chairman of Seadrill Limited, Prosafe SE, Axactor SE and of AqualisBraemar LOC ASA. Mr. Rødland also served on the board of Spectrum ASA for more than 10 years, seven of which as Chairman. Mr. Rødland’s qualifications include an MBA and Postgraduate Studies in Finance completed at the Norwegian School of Economics and Business Administration (NHH) and UCLA. Member of the Committee since 2020.

Herman Kleeven, member (elected until 2022)

Born 1966. Mr. Herman Kleeven is educated from the University of Limburg. From 2013, H. Kleeven has been Head of Focus Equities – APG Asset Management (APG). Previously, he held portfolio management positions at Robeco and was Head of Equity Investments ING Insurance. APG is one of the largest TGS shareholders. Elected as member of the Committee since 2016.

THE CONSIDERATIONS OF THE NOMINATION COMMITTEE.

The Nomination Committee has worked according to the Charter presented to the Annual General Meeting of the Shareholders on June 7, 2011.

The Committee has in this election period communicated with some of the largest shareholders in the Company. The Committee has evaluated the Board’s 2020 Self‐Evaluation Report. The report has also been discussed in detail with the Chairman. In addition, the Nomination Committee has arranged meetings with the joint Board and the Committee Chairman has communicated with TGS Board Members and the CEO on an individual basis.

The Nomination Committee is of the opinion that the nominated Board of Directors will have the necessary qualifications to meet challenges ahead. All Board members have in this election period contributed in a constructive way to the Company`s best interest on and in between Board meetings. In nominating the present Board of Directors, the NC has balanced the need for continuity and renewal.

The Nomination Committee has in this election period experienced no conflict of interest as regards the Board members’ directorships in other listed companies.

All recommendations made by the Nomination Committee are unanimous.

The Committee Chairman has communicated with the Chairman of the Board and the CEO ahead of submitting the Committee`s recommendations.

Oslo, April 02, 2021

Christina Stray Herman Kleeven Glen Ole Rødland Tor Himberg‐Larsen Chairman